Reverse path communication system

ABSTRACT

The Reverse Path Communication System architecture enables end user devices to share a common wireless forward path of a multicast communication architecture in which the forward path delivered content is dynamically changed or modified based on a real-time, near-real-time, or delay-time basis via aggregated reverse path feedback from at least one of a plurality of end user devices. The Reverse Path Communication System periodically or continuously aggregates the feedback input received via the reverse path (having wired and/or wireless connectivity), modifies the forward path multi-media content, and delivers this dynamically modified multi-media content to the then connected population of end user devices via a wireless forward path multicast in a repetitive closed loop fashion.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a Continuation-In-Part of U.S. patent applicationSer. No. 12/675,356 filed Feb. 25, 2010 and U.S. patent application Ser.No. 12/675,349, filed Feb. 25, 2010, and are hereby incorporated byreference to the same extent as though fully disclosed herein.

FIELD OF THE INVENTION

This invention relates to a Reverse Path Communication System whichenables feedback via the reverse path (end user device to networkdirection) from at least one of a plurality of end users who are capableof influencing, modifying, or changing the delivered multi-media contentin the forward path (network to end user device direction) beingdelivered via a wireless multicast communication network and alsoprocessing requests from the end users to purchase goods or servicesidentified in the forward path content.

BACKGROUND OF THE INVENTION

Multi-media content such as video, music, and data is delivered in awell-known fashion via wired or wireless networks to end user devicessuch as HDTVs, music play-back systems, and portable mobile devices.These networks each have unique characteristics of speed, efficiency,reliability, availability, and capacity. For example, satellite is moreefficient for large geographic regions but suffers from diminishedcontent distinction from one region to the next; that is, there isminimal content diversity, and it is expensive and difficult to do highgranularity regional or demographic content targeting in a satellitearchitecture. In contrast, cable TV has regional and neighborhoodtargeting attributes but is often bandwidth or capacity constrained,thereby limiting the number of high bandwidth HDTV signals it can carry.

What is needed is a network architecture that combines the two strengthsof targeting and capacity. An architectural advantage of terrestrialwireless networks is high capacity and targeted delivery. A terrestrialwireless network can deliver multi-media content to more than one enduser or subscriber at the same time, thereby realizing high levels ofnetwork efficiency. The terrestrial wireless network delivery method iscalled broadcast, multicast, or narrowcast and has multiple end users(subscribers) and their associated end user devices receiving thebroadcasted content, and thereby derives its high efficiency when morethan one end user receives the same content in a simultaneous fashion.

Wireless multicast service facilitates the sharing of a single airinterface channel by multiple end users. The single wireless airinterface channel, whether logical or physical, extends from the basestation radio transmitter in the wireless communication network to asubscriber's wireless end user device, wherein the single wireless airinterface channel comprises the forward path (network to end user devicedirection) that carries the multicast multi-media content. A pluralityof end user devices thereby concurrently receive the multi-media contenton the same forward path channel. While the multicast process is welltaught in the art, the delivered multi-media content, information, ordata (collectively termed “content” or “multi-media content” herein) isstatic in nature and is simply a replica of the source content. Thewirelessly multicast source content is immutable and does not have enduser interaction or feedback.

New wireless multi-media content delivery architectures, such asMediaFLO (“Media ForwardLinkOnly”) and DVB-H (Digital VideoBroadcast-Handheld), function by using a broadcast architecture in theforward path to produce a pseudo-multicast delivery and concurrentlydisseminates multi-media content to a plurality of wireless end userdevices on a single air interface channel. In these architectures (alsotermed “multicast” herein), a unidirectional multi-media wirelessbroadcast network transmits multi-media content to selected authorizedwireless end user devices in a time concurrent fashion. However, thereis no interconnection, interaction, or feedback between the end usersand their associated end user devices with this multi-casted multi-mediacontent stream. The forward path content is completely and totallystatic in its nature. The delivered multi-media content is essentiallyno different than UHF or VHF broadcasted television, other than it canbe received on small portable digital devices.

The MediaFLO and DVB-H multi-media wireless architectures, therefore,are static in their user interface, since there is no interactivity orfeedback between delivered multi-media content and the end user. Themulti-casted content is invariant or immutable in its extent. That is,whatever is delivered to the wireless network for transmission to theend user population is delivered as an exact replica, untouched andunmodified from its original form. This is a distinct and inherentlimitation of the present wireless multicasting art (even thoughmulticasting is efficient and targeted).

The existing wireless multicasting art does not enable or permit endusers, via their associated end user devices, to modify the multi-mediacontent carried on the forward path in any manner. Still, there arenumerous applications wherein the ability to modify the forward pathmulticast content based on end user (subscriber) input or actions wouldbe highly desired. What is needed is a novel adaptation of a wirelessmulticast network that enables end user interaction and modification ofthe forward path delivered multi-media content. In this newarchitecture, the end user population would have an unprecedentedability to communicate data and knowledge via the reverse path, acapability heretofore unavailable.

Thus, the state of the wireless multicasting art does not enable thecapability to dynamically modify the content delivered on the forwardpath via aggregated feedback or input from at least one of a pluralityof end users via their associated end user devices. No system heretoforehas envisioned engaging the end user to directly and actively influencethe delivered multi-casted content.

BRIEF SUMMARY OF THE INVENTION

An advance is realized over the present wireless multicasting art by thepresent Reverse Path Communication System, which enables a reverse pathfeedback architecture, wherein the forward path multi-casted content canbe dynamically modified as a result of end user interaction or feedbackand requests can be transmitted from the end user devices on the reversepath. In the Reverse Path Communication System architecture, end userdevices share a common wireless forward path of a multicastcommunication architecture in which the forward path delivered contentis dynamically changed or modified based on a real-time, near-real-time,or delay-time basis via aggregated reverse path feedback from at leastone of a plurality of end user devices. The Reverse Path CommunicationSystem periodically or continuously aggregates the feedback inputsreceived via the reverse path (having wired and/or wirelessconnectivity), modifies the forward path multi-media content, anddelivers this dynamically modified multi-media content to the thenconnected population of end user devices via a wireless forward pathmulticast in a repetitive closed loop fashion. Alternatively or inaddition, the end user population would have an unprecedented ability tocommunicate data and knowledge via the reverse path, a capabilityheretofore unavailable. The scope and diversity of these end user drivenapplications, while virtually unlimited, include: multiplayer gaming,emergency events, education, medicine, live sporting events, automobiletraffic congestion reports, and the like.

The Reverse Path Communication System aggregates the reverse pathfeedback from the end user device or devices and then processes thisfeedback data in context with the streamed forward path content. Forexample, if the application is a multiplayer game, the Reverse PathCommunication System receives the end user's reverse path feedback datawhich defines how their avatar or in-game virtual person should react orbehave at a given point within the game. This feedback is sent to theReverse Path Communication System via wired or wireless means. TheReverse Path Communication System, in this gaming example, aggregatesand delivers the “combined feedback” of all the connected end users forthat moment in time to the gaming software application. The gamingsoftware application then modifies its streamed forward path contentaccording to the latest “combined feedback”. The wireless multicastnetwork then delivers the latest video frames or sequence of successivegame image frames of the game session (to include sound) to theparticipating end users based on the “combined feedback”. The wirelessmulticast can be delivery targeted to regionally or locally grouped enduser sub-populations to enhance the overall network efficiency. Thisprocess repeats in a continuous fashion, with continuous N+1 events of“combined feedback” delivered to the software application, which in turnmodifies the streamed forward path content.

In addition, the Reverse Path Communication System enables thesubscriber to receive the multicast or MediaFLO/DVB-H broadcast on theirwireless subscriber device via the forward path of a multicast/broadcastchannel, concurrently with a plurality of other subscribers on the samemulticast/broadcast channel, and simultaneously initiate a uniquetransaction to purchase goods and/or services or to move information viathe reverse path associated with the shared multicast channel or over areverse path on an associated cellular network, respectively. Typically,goods and/or services are offered to the subscriber as part of themulticast/broadcast extant on the shared forward channel and theindividual subscribers receiving the shared multicast/broadcast canelect to purchase the offered goods and/or services by activating aresponse message that is transmitted over the reverse path, indicatingthe subscriber's desire to initiate a transaction. The subscriber isuniquely identified as part of the registration process, and cancommunicate with the Reverse Path Communication System via the reversepath of the multicast channel, in a secure, subscriber specific manner.This enables the subscriber to signal the Reverse Path CommunicationSystem of their desire to initiate a transaction by signaling on thereverse path of the multicast channel, yet not have to disconnect fromthe multicast channel and originate a separate point-to-pointcommunication connection from the wireless subscriber device to thepoint-of-sale server to initiate and effect a transaction, as isrequired in existing systems.

End users in the Reverse Path Communication System can be grouped vialocation or region, together with personal attributes such asdemographic, socio-graphic, or psychographic interests as it relates toa given multi-casted content stream. The pairing of physical locationgroupings with personal interest attributes enables new and noveltelecommunication services with the attendant advantage of extremelyefficient delivery. The wireless communication network's capacityutilization, both in terms of assets and spectrum, is very high.

For example, the Reverse Path Communication System is ideally suited toblogging and social networking. In a social networking application,personal devices such as a cell phone with cellular or WiFi or WiMaxconnectivity are now capable of connecting to a social network withextremely high efficiency since the forward path link, which isgenerally more bandwidth intensive, is shared as a “grouped multicast”.The social network can be specifically targeted as a given demographic,socio-graphic, or psychographic interest group. Social networks areoften a “thin-thick pipe” in their networking requirements. That is, thereverse path data from any given end user is less bandwidth intensive,but the streamed content back to the population of end users in a givensocial network is generally more bandwidth intensive. Thus, socialnetworks ideally fit the networking profile of the present Reverse PathCommunication System.

In the Reverse Path Communication System architecture, the reverse pathfend user to network direction) can be wired or wireless. Thus, thereverse path has flexibility in terms of its connectivity as well as therelative speed of its connection. For instance, a computer connected toa home or office LAN can use their personal LAN network for reverse pathconnectivity to the Reverse Path Communication System. However, torealize the forward path efficiencies of concurrent delivery of thestreamed content, the computer also has the ability to wirelesslyreceive the concurrent forward path for its sub-population geographicgrouping via cellular, WiFi, WiMax, MediaFLO, DVB-H, or some otherwireless means. Alternatively, if the reverse path is wireless only, theend user device could use the same network as the forward path stream,such as in a WiFi or WiMax network; or it could be a hybrid of WiFi orcellular in the reverse path and MediaFLO in the forward path. The enduser device could be a PC, a PDA, a cell phone, or some specializeddevice like a video game controller. Thus, the Reverse PathCommunication System architecture is not limited to any oneconfiguration.

The Reverse Path Communication System solves a complex problem residentin existing telecommunication architectures by combining reverse pathfeedback with forward path multicasting in numerous novel ways toachieve high delivery efficiency, high subscriber targeting, andcontinuous content modification ensuring high relevancy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate, in block diagram form, the overallarchitecture of a typical Reverse Path Communication System;

FIG. 1C illustrates an example physical wireless network with reversepath modification of the forward path;

FIG. 2 illustrates the interrelationship between a series of forwardpath multicasts and sub-populations of end users with reverse pathfeedback;

FIG. 3 illustrates, in block diagram form, overlapping user groups;

FIG. 4 illustrates, in block diagram form, where the user groupscreating the content can receive their own collective modified contentor content from other user groups;

FIG. 5 illustrates, in block diagram form, the time alignment of reversepath data to insure forward path modification accuracy;

FIG. 6 illustrates, in flow diagram form, the macro process steps thatthe Reverse Path Communication System takes to complete a continuousforward path modification cycle;

FIG. 7 illustrates, in block diagram form, a typical end user device;and

FIG. 8 illustrates, in flow diagram form, the process to modify forwardpath video and audio based on aggregated reverse path inputs.

DETAILED DESCRIPTION OF THE INVENTION

Philosophy Of The Multicast Wireless Communication System

An exemplary multi-cast technology is described in detail in U.S. Pat.No. 6,594,498 and U.S. Pat. No. 6,681,115, for example; and thistechnology can be used to implement narrowcast communications towireless end user devices where the narrowcast is a highly targeted“multicast” to geographic and/or demographic end user groupings. Theterm “narrowcast” as used in these patents is considered a form ofmulticasting.

Forward Path Multi-Media Management Philosophy

FIGS. 1A and 1B depict a logical or functional description of theForward Path Multi-Media Management System architecture and show theessential building blocks of the overall system. One key element of thisparticular architecture is that the content sources are centrallylocated. FIG. 1C illustrates one physical network embodiment of thesystem of FIGS. 1A and 1B.

Content sources 105-107 are centrally located and typically sources ofbroadband multi-media programs that are either generated off-line ordynamically generated on-line. The content could be visual orvisual/aural in its extent, or it could take some other form such asmachine-to-machine data. This content is of interest to one or moregrouped sets of end users (subscribers) on the forward path multicast.

End user devices that receive the content can be grouped by region,locale, or geography as sub-populations 160-163 where sub-population 163is the Nth sub-population. In aggregate, all of the sub-populations formthe “population” of end users. While not shown, these sub-populationscould also be formed on the basis of end user attributes such asdemographic, psychographic, or socio-graphic attributes; thus, thegrouping may be logical and not physical. With this type of attributematching, the grouping takes the form of a logical group versus aphysical group and can be characterized also as a sub-population orpopulation. The attribute grouping could also be paired with a physicalgrouping such that end users can be both logically and physicallygrouped to form a multicast sub-population.

The grouping process, be it geographic-, attribute-, orcombinatorially-based, is accomplished via methods well understood inthe art. To realize geographic grouping, the GPS position can be mappedto a given radii, and all end users within that radii are grouped. Forattribute grouping, the end user or subscriber attributes are stored ina database such as a Home Location Register (HLR) if the wirelessnetwork is cellular; then all end users with the requisite attributesare logically joined as a group independent of their physical location.Alternatively, both “grouping” methods, geographic and logicalattribute, are combined to provide highly targeted delivery, both bylocation and by needs. Other grouping methodologies are possible, andnothing herein limits how groups are formed. The groups that are definedare used by content routing and formatting element 149 shown on FIG. 1Bto activate the network to deliver a particular stream of content to thegrouped end user devices and in a format that matches their particulardisplay and function characteristics.

Reverse Path Communication System 118 has three building blocks: VirtualFeedback Aggregator 120 acts as a communication device and buffer tocollect and aggregate all of the reverse path information; ContentProcessor 130 acts as an information processor where softwareapplications reside and process the aggregated inputs from the connectedend user devices; and Content Integrator 140 performs the functionalityof modifying the selected multi-media content stream. The modificationby Content Integrator 140 could be a video frame processor, it could bean audio stream modifier, or it could be both, for example.

Content Processor 130 has algorithms to determine how N reverse pathmodifier inputs should be collectively assimilated and then sent toContent Integrator 140 for content modification. Content Processor 130determines how to apply the collective inputs for a given processingstep performed in Content Integrator 140. There is at least one residentsoftware application, and there could be multiple software applicationsconcurrently operating. The inputs include, but are not limited to: whatregion an end user device is in (useful for forming the forward pathmulticast region); what sensor data the device is sending, such asHazMat information; what the GPS location is of a given device; is therea “user input” such as an action or motion for a gaming application; andso on. In addition, the functionality described can be implemented invarying ways, so the assimilation of the modifier inputs and/or theirapplication to a process for modification of the content stream maydiffer from that described herein.

Reverse path 170 originating in FIG. 1B and connected to Reverse PathCommunication System 118 and internally to Virtual Feedback Aggregator120 provides a method where end user devices in groupings 160, 161, 162,and 163 communicate data for the modification procedure that ultimatelyoccurs at Content Integrator 140. This completes a continuous processingcycle end-to-end across the Reverse Path Communication System 118.

The Reverse Path Communication System 118 enables the functions ofaggregation of reverse path content at Virtual Feedback Aggregator 120.The reverse path content conveyed from content sources 105-108 iscomprised of content that is multi-media in nature which is uploaded tothe Content Integrator 140 of the Reverse Path Communication System 118.In addition, the Virtual Feedback Aggregator 120 can redirect thereverse path content to external destinations, such as the cloud orcontent sources 106-108 via paths 110A-113A. For example, the reversepath content received from an end-user device can be stored on anexternal memory via IP network 181 for later use by the user.

It is anticipated that the preferred embodiment has a feedback loopcomprising reverse path 170 as the content modification data link; andpaths 110, 111, 112, and 113 are used primarily for content sourcepaths. In addition, the path components 110A-113A, where links 110-114are bidirectional links, are shown as directly connected to the contentsources 105-108 to illustrate how the forward path multi-media contentcan be modified directly at the content generating content sources105-108. In this architecture, the content sources 105-108 embody acontent processing capability similar to the Reverse Path CommunicationSystem 118.

Content Integrator 140 can have a number of applications, and the listedapplications in no manner suggest that this is the entire set ofapplications that the Reverse Path Communication System is capable ofimplementing. In addition, the applications illustrated herein can beimplemented as an integral part of the Reverse Path Communication System118, or can be sites that are located external to the Reverse PathCommunication System 118. These external sites can be existing contentgenerating and processing systems, such as a massively multiplayerrole-playing game (MMORPG) which enables players located at diverselocations to form sub-groups, tribes, or armies within the game space.

The applications illustrated in the Reverse Path Communication System118 are for illustration, and multi-player application 141 is a gamingprocess that implements multi-player gaming or live multi-partyinteractive competitions. Morphing Area process 142 uses the receivedreverse path feedback data to map a geographical locus and region of aphysical phenomenon that is detected by a plurality of the end userdevices, such as the presence of a BioHazard. Education application 143represents an education application where a student or students can askprofessors questions of a live multi-casted classroom lecture. PersonalMedicine application 144 is a multi-party medical feature, such as asupport group for cancer. Traffic reporting application 145 uses thefeedback received from the end user devices to map road conditions onthe various highways that are being traversed by the end users. As partof this, the smart cars can communicate with each other as well asstationary sites to generate alerts for accidents, construction zones,detours etc. They will likely be cell network based and the stationarylocations especially will need to narrow cast as may the vehiclesthemselves. That opens up Reverse Path as a way for the car tocommunicate back. So a construction zone multicasts it's status toapproaching cars and the cars tell the construction zone that they areapproaching the construction zone, which updates traffic volume in realtime. Blogging application 146 provides the end users with a venue topost blogs. Personal video upload service 147 enables the end users toupload multi-media files for sharing among end users. Social networkingapplication 148 represents any multi-party communication site.

The output of these various services and applications are transmitted tocontent routing and formatting element 149 for display formatting androuting to end user groups. These outputs are then transmitted viacommunication path 150 to effect a multicast of the modified contentwhich is transmitted to the end user devices via the forward path 155 ofthe communication network. Forward path 155 connects to end usergroupings 160, 161, 163 and to end-user device 162. As an example,grouping 160 contains end user devices 1, 2, 57 which are unique toRegion 1; the forward path to this grouping could be via MediaFLO, forexample. In grouping 161, Region N's end user devices 2-10 and 15, 18,105 might be connected via forward path 155 as a WiFi architecture. InRegion 2, the listed end user devices could be connected via forwardpath 155 as a DVB-H signal. The Single Device 162 may be in a veryremote area, so it uses a mobile satellite to receive forward path 155.

Cellular Network Implementation

FIG. 1C illustrates one embodiment of a physical implementation of thesystem of FIGS. 1A and 1B. In FIG. 1C, a cellular network is depicted,but other network architectures are capable of realizing Reverse PathCommunication System functionality. Of note, certain cellular buildingblocks are not shown for concept clarity; the devices not shown includebut are not limited to: Home Location Register (HLR), Visitor LocationRegister (VLR), Mobile Switching Center (MSC), Packet Data SwitchNetwork (PDSN), and so on. The function and interconnection of thesedevices is well known in the art.

Radio Network Sub-System 182 and Radio Network Sub-System 183 are shown,and each Radio Network Sub-System serves a unique geographic region.Cell site 198 serves end user devices 189 through 190, and cell site 199serves end user devices 194 through 195. Cell site 198 could beomni-directional in its coverage extent, while cell site 199 could besectorized in its coverage. Further, end user devices 189-190 aregrouped together because they are receiving a common multicast fromRadio Network Sub-System 182 via cell site 198 along RF forward path186. Likewise, end user devices 194-195 are receiving a common multicastfrom sectorized cell site 199 via RF forward path 191. However, on thereverse RF path, end user device 189 communicates via RF pathway 187,while end user device 190 communicates on the reverse path via RFpathway 188; and end user device 194 communicates on reverse path 192,while end user device 195 communicates via reverse path 191.

In a process well understood in the art, a mobile device (end userdevice) could move from sectorized cell site 199 to omni-directionalcell site 198 and retain seamless coverage via the handoff or handoverprocess. Handoffs can be hard, meaning the previous signal is droppedbefore the new signal is acquired, or they can be soft, where both cellsites 198 and 199 would have communication for a period of time untilthe handoff is completed. Separately, within the sectored cell site 199,a “softer” handoff process can occur wherein the end user deviceoperates on two adjacent coverage sectors of cell site 199 at the sametime.

To initiate a forward path modification sequence, a content modificationsignal is sent across the physical network. Tracing the path of oneexample reverse path signal, end user device 189 would communicate viareverse path 187 to cell site 198, which then communicates with RadioNetwork Sub-System 182. End user device 182 then communicates with dataswitch/router 180 to the network 181. Network 181 contains all thetypical networking formats to include Public Telephone Switched Network(PSTN), Public Switched Data Network (PSDN), and an Internet ProtocolNetwork (IP Network). In addition, while not shown, other protocols thatare more suited to a mobile architecture may be deployed.

The network 181 is connected to end user devices 184 and 185 via a moretraditional wired paradigm. Reverse Path Communication System 175 isconnected to network 181, Reverse Path Communication System 175 receivesreverse path modification information from all the then connected enduser devices, and processes the data in a manner described herein. TheSource Content site 177 delivers content to Reverse Path CommunicationSystem 175; content can be multi-media or any other data form that hasrelevance to the subscriber population or sub-population. After theReverse Path Communication System has performed its operations, itforwards the modified forward path content back to network 181. Network181 then communicates to router 180, then radio network subsystem 182and cell site 198 finally transmit the modified forward path content viaRF path 186 to end user devices 189-190, respectively. This processrepeats in a cyclical fashion, starting with reverse path modificationinformation to the Reverse Path Communication System 175, which thenmodifies the forward path content on a frame-by-frame basis if video,and then back to the end user devices.

Gaming Representative Architecture

FIG. 2 illustrates, in broad perspective macro block diagram form, how atypical gaming application might be architected. For this description,the card game of blackjack gambling is used; however, nothing in thisexample description limits the applicability of the described conceptsto other applications with similar attributes.

At Reverse Path Communication System 201, the reverse path feedback datais aggregated from reverse path 240. The data coming into Reverse PathCommunication System 201 originates from end user devices located on theright side of FIG. 2, shown as squares with alpha or number designators(to be discussed more later in this section). This feedback data couldbe instructions such as: “I'll take another card” or “I want to doubledown” or “I fold and am out for this game only” or “I am done playingentirely”. For blackjack, the “dealer” is a software applicationresiding as an external network connected device 202, calledApplication. This software application 202 responds to the feedback datacollected by Reverse Path Communication System 201 and then creates andprovides modified content via connection 205 to forward paths 210, 212,and 214. Likewise, any other application, be it multi-player gaming orthe like, would operate in a similar fashion.

Nothing herein limits what form forward paths 1, 2, and N, respectively210, 212, and 214, take. Thus, forward path 210 could be WiFi, forwardpath 212 could be MediaFLO, and forward path 214 could be cellular, eachof which comprise an air interface for the forward path. Forward paths210, 212, and 214 can also be characterized as a physical deliveryregion, or could be characterized as a combined physical and logicaldelivery region/method, respectively, or just a logical delivery method.If forward paths 210, 212, and 214 are logical delivery paths, then thedelivery methodology is related to pairing of end users with a givenforward path's content, where the end users have like interestsindependent of physical location. The actual physical delivery regionsof these forward paths could be highly varied and diverse. For example,forward path 210 may just be a single narrowcast to a neighborhood in acity on a Caribbean island where electronic gambling is legal. Incontrast, forward path 212 could be to all the major gambling areas inthe world. For forward path 212, since it is covering so many diversegeographic regions, the air interface of the forward path, be it DVB-H,or MediaFLO, can vary; and nothing herein limits what method is used todeliver the reverse path modified content on the forward path. Finally,forward path 214 might be to all college campuses in the state of Nevadathat have more than 2000 students.

The modified forward path content is sent via connection 220 which, asalready discussed, could take the form of a variety of wireless airinterfaces. The Population 230 comprises the complete set of thenconnected Players or End Users and their associated End User Devices.Within this Population 230 of the then connected end user devices,Sub-Populations 231-233 are present. These Sub-Populations 231-233 maybe geographically concentrated to enable an efficient forward pathmulticast, narrowcast, or broadcast delivery; or these Sub-Populations231-233 may be defined as the set of all Players or End users that areblackjack aficionados (i.e., a logical grouping). Again, this latterdescription is more logical in its extent. Thus, Sub-Populations 231-233may be logically based on demographics, for example, physically based onlocation, or the Sub-Populations 231-233 could be a combination of each“grouping methodology”. For instance, in Sub-Population 231, end userdevices A and B may be in the same geographic region as end user devicesM and N in Sub-Population 232, and so a single physical air interfacenarrowcast (WiMax, for example), is set up to deliver the modifiedforward path content to end user devices A, B, M, and N, since they aregeographically close or in some air interface proximity to each otherand within the coverage region of the WiMax cell.

Alternatively, Sub-Populations 231-233 could all be geographicallydefined, and the logical grouping of those end users interested inblackjack has already been defined by the system. In this case, threemulticasts would be set up to deliver modified forward path content tothese three geographic regions. Individual Users having end user devices234, 235, 236, and 237, the Nth device, would each have their ownphysical air interface connection to the modified forward path content.

In aggregate, the entire Set or Population 230, in some pre-specifiedtimeframe, provides feedback via reverse path 240 to Gaming System withReverse Path Feedback 201, all in a continuous fashion until a givenblackjack game is complete, when a new game is started, or when thescheduled time for blackjack is over, for example.

Logical Architectures

In FIG. 3, content sources 1-10 individually and in aggregate createcontent which is supplied to the network. Content sources 1-10 then areconnected via conductors 303, which could be wired or wireless in itsextent, to Reverse Path Communication System 305. Reverse PathCommunication System 305 aggregates the content from content sources1-10, as applicable, and then applies this data to the Application, forthis example residing within Reverse Path Communication System 305. TheApplication at Reverse Path Communication System 305 then provides inputto modify the streamed forward path content to update the end userdevices in a continuous fashion, via wireless forward path 307, as apreferred embodiment already described herein. The delivery of themodified forward path content is sent to, in this example,sub-populations 310 and 320. These sub-populations in this particularexample are geographic in their extent; that is, the end user devicesare within the geographic region of a common shared forward path. Thus,in this embodiment, the chain of communication and content conveyanceinitially derives from end users that are logically grouped to end usersthat are now geographically grouped. While the description heretoforehas described a logical to physical grouping, there is nothing hereinthat limits other types of grouping pairs such as: logical to logicalgroupings, physical to physical groupings, or physical to logicalgroupings.

At the content source origination point 300, with central contentsources 1-10, the conveyed content the is collectively aggregated andprocessed at Reverse Path Communication System 305 according to theapplication residing at Reverse Path Communication System 305, and thendelivered back to these same end user devices, wherein the forward path307 content has been modified based on end user input(s). Thus, atdelivery region 310, in this example, end user devices 1, 2, and 6-10are all physically proximate within a given multicast, narrowcast, orbroadcast region of the given forward path 307 for that geographicregion and share a common air interface or channel which coveys modifiedforward path content to the end user devices. Likewise, in deliveryregion 320, end user device 3 is wholly and uniquely served by forwardpath multicast delivery region 320. However, end user devices 4-5 canreceive the modified forward path from either delivery region 310 or320. More importantly, it may not be an either/or reception decisionfrom the end users perspective, that is to select just delivery region310 or just delivery region 320. In fact, the reception could be in softor softer handoff, wherein wirelessly conveyed information is receivedand combined in a known fashion from both delivery regions 310 and 320(this is typically a CDMA architecture which more easily enables thebest path selection of N&M paths on a bit-by-bit basis and outputs amore error free data stream than if just N or M were singly selected).

In FIG. 4, a second set of content sources 420 is added; however,nothing herein limits the number of User Groups supplying forward pathmodification information (via the reverse path). Content source group 1has content sources 10-15. Content source group 2, in a similar fashion,has content sources 32-39. In aggregate, content sources 10-15 and 32-39create and communicate content via reverse paths 415 and 425,respectively. The form of the conveyed reverse path data could beoriginal pictures, video, and/or music created by the end user or enduser devices; or it could be forward path modification data such as in agaming, gambling, or hazmat application. Thus, there is nothing thatlimits what is conveyed on the two reverse paths 415 and 425. Reversepaths 415 and 425 could themselves be shared in some air interface, suchas in the time domain or code domain, where a given frequency allocationis fixed; the sharing could be multi-frequency such as in frequencyhopped spread spectrum; or the reverse path could be of the wired form,or a combination of wired and wireless. The reverse path may be uniqueto some or all the end user devices, such as in a circuit switchedconnection. Last, the reverse path could be packet switched in nature.Thus, the access method (TDMA, CDMA, and the like) the modulation (PSK,QAM, and the like) the frequency, or wired vs. wireless is not alimitation of this invention. Generic reverse paths 415 and 425 connectto the Reverse Path Communication System 430.

An example of the dynamic grouping of end used devices is a trafficreporting and management process 145, where the vehicles at, near and/orapproaching a traffic accident or congestion site are grouped based ontheir physical location. Each vehicle (end-user devices A-F in Sub Group1 on FIG. 2) transmits status information to the Reverse PathCommunication System 118, where the traffic reporting process 145evaluates the data contained in the status information transmitted bythe vehicles to determine which data is most relevant to the reportsthat are being transmitted to the collected end-user devices. Thus, thevehicles proximate to the accident or congestion site are likely to havetheir feedback weighed heavier than the data received from vehicles thatare further away. In addition, the dynamic grouping of vehicles can bedone as a function of the significance of the status informationreceived from the vehicles.

In FIG. 4, forward paths 440, 441, and 442, in this example, are allshared and are wireless in nature. The wireless forward paths arearchitecture, modulation, access, and frequency independent. Thus,forward paths 440, 441, and 442 could all be the same architecture, orthey could be different architectures; the selected architecture orarchitectures for forward paths 440, 441, and 112 may be geographicallystatic or they could move or morph as the population or sub-populationof end users or end user devices moves. These forward paths could beWiFi, WiMax, MediaFLO, DVB-H, cellular, satellite, Sirius Radio, XMRadio, or some other type of architecture that enables sharing of theforward path to given groupings of end users. In this example, thecontent sources previously discussed, 10-15 and 32-39, are formed intotwo logical groupings comprising three forward path physical deliveryregions. End User Group D is receiving one content stream via forwardpaths 440 and 441. End User Group C is receiving content via forwardpaths 441 and 442.

In End User Group D, end user devices 32 and 39, along with end userdevices 10-12 and end user device 38, are all receiving the samemulticasted content via forward paths 440 and 441, respectively. Thatis, shared forward path 440 serves end users 32 and 39, while sharedforward path 441 serves end users 10-12 and end user 38, each pathconveying like content to these end users.

Shared forward path 441 is also used to convey a second set of contentto End User Group C. In this example, end users 10-12 and end user 38are receiving two sets of forward path content via forward path 441, oneset for End User Group D and the other set for End User Group C. Thus,it is possible to have overlapping forward path logical delivery regionsby logical addressing of delivery where a given shared forward path isconveying different sets of content over the same air interface to ashared physical delivery region.

End user devices 13-15 and 33-37 are served via shared forward path 442via a wireless means. While the preferred forward path is wireless,since it can be shared, thereby increasing network efficiency andminimizing delivery cost, it is possible to have forward path 442 be awired Internet Protocol (IP) where a packet switched architectureconveys the content to the end user devices via a more traditional wiredmeans (where wired could be copper cable, DSL, cable modem, fiber optic,or other such means).

Reverse Packet Timing

FIG. 5 illustrates, in block diagram form, the time alignment of reversepath data to ensure forward path modification accuracy. In FIG. 5, formost applications, it is important to time align the reverse path packetset 510 comprising packet streams from end user devices 1-N. This istrue for applications such as gaming, where the players' data needs tobe aggregated, again within some time window as noted above; otherwise,the modified forward path content appears out of context or nonsensical.FIG. 5 illustrates the functional operation of a Gaming System With EndUser Feedback 520 to address the packet timing issue.

Gaming System With End User Feedback 520 includes a data buffer 521,located in the feedback aggregator 120, which stores the receivedreverse path end user feedback packets until they can be time sequenceordered by a timing processor 522 in the content processor 130 (withinsome time window), and then forwarded to the delivery networks viacontent integrator 140. Reverse path packets that arrive outside of thetime window for aggregation would be discarded or delayed for use in thesuccessive time interval, based on the operation of the multi-playergaming application 141. Thus, a blackjack player can wager only when itis their turn to wager and can play and receive cards only when it istheir turn to play. If a player attempts to wager or play cards out ofturn, their input will be discarded in order to maintain the integrityof the game.

Furthermore, when the player plays or receives cards, the displays mustaccount for these changes. In the instance where the cards are playedface up, the display transmitted via the unidirectional forward path toall the players is updated. In the case where face down cards arereceived by a player, the player must receive a display of their newcards, but the other players must not be able to see the face downcards. Thus, the forward path of the bidirectional link 170 can be usedto transmit a display update to the player's associated end user deviceto show only the player their face down cards, such as in a split screendisplay. This private data can also be transmitted to the player via theunidirectional forward path 155 as an in-band encrypted data stream,which only the one player can decrypt using their personal decryptionkey. Thus, multiple private data transmissions can be included in theunidirectional forward path 155 transmission if they aretime-interleaved and encrypted.

Process For Modifying The Forward Path

In FIG. 6, a typical process for modifying the content that istransmitted on the forward path is described. This is merely one of anumber of methods to modify the content that is transmitted on theforward path and is not meant to be the only means for such forward pathmodification.

At step 610, the entire population of then connected end user devices isshown. The Reverse Path Communication System is not limited to where theend user devices are physically located. End User Device 1 (611), alongwith End User Device 2 (612) and End User Device “N” (613), respond tothe most recent forward path content, such as the display on a hand-heldvideo game, and initiate a reverse path communication via their end userdevice at step 620, such as how to move their avatar in an action game.At step 630, the Reverse Path Communication System receives andprocesses the reverse path inputs from the then connected end userdevices. Step 630 would also implement the steps of FIG. 5 to insuretime coherency in the aggregated responses.

At step 640, the forward path content, still to be delivered back to theconnected end user population, is modified. Thus, in this gamingapplication, the next frame (or number of frames) of the game ismodified based on the collectively aggregated reverse path inputs. Atstep 650, the game video and audio is delivered via a shared forwardpath. The delivery can be via physical grouping, logical grouping, or acombination of the two forms of grouping. At step 655, the game videoand audio is delivered via a one-to-one communication means, eitherwired or wireless.

At step 660, the feedback loop starts again where the end users viatheir end user devices begin to respond to the new video and audio beingdisplayed on their end user devices. Step 660 connects to step 630 in acontinuous fashion until the game is complete or some other decision forgame termination is realized, such as a time or date. In addition, atstep 670, the end user feedback can be destined for selected ones of theother players in the multi-player game so a player can team with otherplayers in a personal end user device to end user device communicationlink over the bidirectional links.

End User Device

FIG. 7 depicts a block diagram of one embodiment of an end user device.This particular embodiment of end user device 800 has multiple means tocommunicate, as well as numerous means to provide input to ultimatelymodify the forward path. The description of this device is likely moreencompassing than would be for a typical end user device. Thedescription contained herein is meant to show what is possible.

End user device 800 is capable of receiving content multicasts,broadcasts, or narrowcasts on the forward path. End user device 800,either in an autonomous mode or via end user action, then is capable ofcommunicating, in the reverse path direction, end user initiated contentwhich could be complete in its nature; or it could be used (inaggregate) to modify the next few frames of a video game, for instance,after processing by the Reverse Path Communication System.

The central portion of end user device 800 is baseband and RF processor810 which also contains an application processor with associatedsoftware/firmware. Baseband and RF processor 810 manages the operationof end user device 800 by collecting inputs from input devices 830-835and 850, communicating via devices 801 through 806, and outputtingcontent, information, and data via devices 814-816. Baseband and RFprocessor 810 contains typical elements, such as a microprocessor withassociated memory and firmware, as well as loadable software. Inputdevices 830-835 are internally connected to relevant internal componentsvia internal local network 851. They communicate directly with basebandand RF processor 810.

Device 830 is a motion sensor which could be used for gaming. Thisdevice has sensors for acceleration and/or motion; the data collectedcould be relative or absolute. Device 831 is an electronic cash accountwhich provides for a secure means to store cash or cash equivalents onend user device 800 to include a means to send or receive cash or cashequivalents. The electronic cash account could be used to pay foraccessing forward path modified content. This sub-device could also bean electronic credit card or some other electronic payment means likePayPal™.

Device 833 is a digital camera. Device 834 is a digital video camera.Device 835 is a microphone for audio input. Again, as previouslydescribed, all of the input sub-devices 830-835 are internally connectedwithin end user device 800 via local network 851; sub-devices 830-835also receive power and other signaling via 840, battery/buss. Device 850is a keypad or touch-screen. This is an input device connected tointernal network 851. Communication devices 801-806 are generallywireless in nature, but communication device 806 could be wired. Aspreviously discussed, most end user devices would not have this manymethods to communicate; rather, the end user device would have a subsetof the means listed herein.

Device 801 is typically a satellite receiver for a data service from ahigh powered satellite such as Sirius Radio or XM Radio. It could alsobe future satellites such as those from Mobile Satellite Ventures (MSV).The advantage of satellite signals is that they can cover a very largegeographic area for conveying the modified forward path. For MobileSatellite Ventures, their architecture intends to use spot beams, albeitstill covering a relatively large geographic area. Device 801 could alsobe a bi-directional satellite transceiver, meaning it could alsotransmit as well as receive from satellites.

Device 802 is a cellular transceiver. It could be multi-frequency mode,multi-access mode (GSM and CDMA), or it could be multi-air interfaceprotocol, such as 1xRTT and EVDO. Device 803 is a WiFi transceivergenerally conforming to the “802” standards. Device 804 is a WiMaxtransceiver. WiMax networks are being deployed as of this filing andoffer the advantage of wider area coverage(longer link distances) thandoes WiFi, which generally is considered and used for shorter distancecommunications. For either WiFi or WiMax, the communication is typicallypacket switched and uses versions of the IP protocol, albeit wirelessly.Device 805 is a very short range Bluetooth transceiver. Device 806 issome other communication means to include wired communications.

The output devices of end user device 800 are 814-816. Device 814 is amotion output device. This could be a shaker or something moresophisticated, such as that in the Wii™ video game controller. It isdesigned to provide physical, sensory feedback to the end user or enduser device. Device 815 is a video display. The display is likelydigital in nature and would provide a high resolution (a large number ofpixels) image capable of displaying images, video, games, and the like.It is anticipated that end user device 800 could also communicate animage, video, or visual information via a short range means such asBluetooth to a remote monitor or display. Device 816 is for audiooutput. It could be via speakers mounted on the end user device, viawired or wirelessly connected headphones, or via a Bluetooth connectionto a remote sound system, for example.

As part of the content delivery, the system can deliver AugmentedReality (AR) which is a live direct or indirect view of a physical,real-world environment whose elements are augmented (or supplemented) bycomputer-generated sensory input such as sound, video, graphics or GPSdata. It is related to a more general concept called mediated reality,in which a view of reality is modified (possibly even diminished ratherthan augmented) by a computer. As a result, the technology functions byenhancing one's current perception of reality. By contrast, virtualreality replaces the real world with a simulated one. Augmentation isconventionally in real-time and in semantic context with environmentalelements, such as sports scores on TV during a match. With the help ofadvanced AR technology (e.g. adding computer vision and objectrecognition) the information about the surrounding real world of theuser becomes interactive and digitally manipulable. Information aboutthe environment and its objects is overlaid on the real world. Thisinformation can be virtual or real, e.g. seeing other real sensed ormeasured information such as electromagnetic radio waves overlaid inexact alignment with where they actually are in space.

A head-mounted display (HMD) is a display device paired to a headsetsuch as a harness or helmet. HMDs place images of both the physicalworld and virtual objects over the user's field of view. Modern HMDsoften employ sensors for six degrees of freedom monitoring that allowthe system to align virtual information to the physical world and adjustaccordingly with the user's head movements. HMDs can provide usersimmersive, mobile and collaborative AR experiences. Near eye augmentedreality devices can be used as portable head-up displays as they canshow data, information, and images while the user views the real world.Many definitions of augmented reality only define it as overlaying theinformation. This is basically what a head-up display does; however,practically speaking, augmented reality is expected to include trackingbetween the superimposed information, data, and images and some portionof the real world.

Spatial Augmented Reality

Spatial Augmented Reality (SAR) augments real world objects and sceneswithout the use of special displays such as monitors, head mounteddisplays or hand-held devices. SAR makes use of digital projectors todisplay graphical information onto physical objects. The key differencein SAR is that the display is separated from the users of the system.Because the displays are not associated with each user, SAR scalesnaturally up to groups of users, thus allowing for collocatedcollaboration between users.

Examples include shader lamps, mobile projectors, virtual tables, andsmart projectors. Shader lamps mimic and augment reality by projectingimagery onto neutral objects, providing the opportunity to enhance theobject's appearance with materials of a simple unit—a projector, camera,and sensor.

Other applications include table and wall projections. One innovation,the Extended Virtual Table, separates the virtual from the real byincluding beam-splitter mirrors attached to the ceiling at an adjustableangle. Virtual showcases, which employ beam-splitter mirrors togetherwith multiple graphics displays, provide an interactive means ofsimultaneously engaging with the virtual and the real. Many moreimplementations and configurations make spatial augmented realitydisplay an increasingly attractive interactive alternative.

A SAR system can display on any number of surfaces of an indoor settingat once. SAR supports both a graphical visualisation and passive hapticsensation for the end users. Users are able to touch physical objects ina process that provides passive haptic sensation.

Tracking

Modern mobile augmented reality systems use one or more of the followingtracking technologies: digital cameras and/or other optical sensors,accelerometers, GPS, gyroscopes, solid state compasses, RFID andwireless sensors. These technologies offer varying levels of accuracyand precision. Most important is the position and orientation of theuser's head. Tracking the user's hand(s) or a handheld input device canprovide a 6DOF interaction technique.

Virtual reality or virtual realities (VR), which can be referred to asimmersive multimedia or computer-simulated reality, replicates anenvironment that simulates a physical presence in places in the realworld or an imagined world, allowing the user to interact with thatworld. Virtual realities artificially create sensory experience, whichcan include sight, touch, hearing, and smell.

Most up-to-date virtual realities are displayed either on a computerscreen or with an HD VR special stereoscopic displays, and somesimulations include additional sensory information and focus on realsound through speakers or headphones targeted towards VR users. Someadvanced haptic systems now include tactile information, generally knownas force feedback in medical, gaming and military applications.Furthermore, virtual reality covers remote communication environmentswhich provide virtual presence of users with the concepts oftelepresence and telexistence or a virtual artifact (VA) either throughthe use of standard input devices such as a keyboard and mouse, orthrough multimodal devices such as a wired glove or omnidirectionaltreadmills. The immersive environment can be similar to the real worldin order to create a lifelike experience—for example, in simulations forpilot or combat training—or it can differ significantly from reality,such as in YR games.

Modified Multi-Media Content

FIG. 8 is a representative flowchart for modifying multi-media content.At step 910, the reverse path inputs from the then connected end usersare aggregated in a fashion already described herein. At step 920,individual frames of the visual content are modified; and at step 930,the aural information is also modified. At step 940, in a timesynchronous fashion, the visual and aural information is re-integrated.Step 950 determines if there is enough modified content to send via theforward path. If there is sufficient modified forward path data, at step960, the modified content is sent via a shared forward path. However, atstep 950, if sufficient frames are not ready to be sent, step 950buffers the completed modified frames and then returns to the processflow back to step 910 to create more modified frames until such time asthere are sufficient frames to send, application determinate.

SUMMARY

The Reverse Path Communication System architecture enables end userdevices to share a common wireless forward path of a multicastcommunication architecture in which the forward path delivered contentis dynamically changed or modified based on a real-time, near-real-time,or delay-time basis via aggregated reverse path feedback from at leastone of a plurality of end user devices. The Reverse Path CommunicationSystem periodically or continuously aggregates the feedback inputsreceived via the reverse path (having wired and/or wirelessconnectivity), modifies the forward path multi-media content, anddelivers this dynamically modified multi-media content to the thenconnected population of end user devices via a wireless forward pathmulticast, in a repetitive closed loop fashion.

What is claimed:
 1. A Reverse Path Communication System, operational ina wireless communication network which serves a plurality of wirelessend user devices comprising: a content distribution server, connected toa multi-casting wireless network that serves a plurality of wireless enduser devices, for simultaneously transmitting a stream of content framesreceived from a content source to a plurality of wireless end userdevices, comprising a set of selected ones of wireless end user devices,over a single unidirectional forward broadcast path of the multi-castingnetwork that extends from the content distribution server to theselected wireless end user devices; a private reverse path, concurrentlyoperational with the unidirectional forward broadcast path, fortransmitting end user input data received from the at least one of theselected ones of the wireless end user devices in response to the streamof content frames transmitted over the unidirectional forward broadcastpath; wherein the content distribution server comprises: a feedbackaggregator for receiving end user input data received from the set ofselected ones of wireless end user devices and routing the end userinput data to one of an external destination and a content processor foridentifying modifications to the stream of content frames correspondingto the aggregated end user input data.
 2. The Reverse Path CommunicationSystem of claim 1 wherein the content distribution server furthercomprises: a content integrator, responsive to identified modificationsto the stream of content frames corresponding to the aggregated end userinput data, for dynamically modifying the stream of content frames yetto be transmitted to the set of selected ones of wireless end userdevices and transmitting the modified the stream of content frames tothe set of selected ones of wireless end user devices.
 3. The ReversePath Communication System of claim 1 wherein the content distributionserver further comprises: a feedback synchronizer for associating theend user input data received from the end users with correspondingstream of content frames.
 4. The Reverse Path Communication System ofclaim 2 wherein: the feedback aggregator further comprises: a timingsynchronizer for defining a time period for use by the feedbacksynchronizer during which time period the end user input data receivedfrom the end users is associated with at least one of the present framesof the stream of content frames stored in the buffer.
 5. The ReversePath Communication System of claim 4 wherein the feedback aggregatorfurther comprises: an accumulated feedback data processor for processingthe accumulated end user input data received from the end users to acomposite content revision for stream of content frames.
 6. The ReversePath Communication System of claim 1 further comprising: a contentfeedback generator for transmitting end user input data, associated withcorresponding stream of content frames, to a central content source thatis generating the corresponding stream of content frames via a path thatextends from the communication network to the central content source. 7.A method of operating a Reverse Path Communication System, operationalin a wireless communication network which serves a plurality of wirelessend user devices comprising: simultaneously transmitting from a contentdistribution server, connected to a multi-casting wireless network thatserves a plurality of wireless end user devices, a stream of contentframes received from a content source to a plurality of wireless enduser devices, comprising a set of selected ones of wireless end userdevices, over a single unidirectional forward broadcast path of themulti-casting network that extends from the content distribution serverto the selected wireless end user devices; transmitting over a privatereverse path, concurrently operational with the unidirectional forwardbroadcast path, end user input data received from the at least one ofthe selected ones of the wireless end user devices in response to thestream of content frames transmitted over the unidirectional forwardbroadcast path; wherein the step of simultaneously transmittingcomprises: receiving end user input data received from the set ofselected ones of wireless end user devices and routing the end userinput data to one of an external destination and a content processor foridentifying modifications to the stream of content frames correspondingto the aggregated end user input data.
 8. The method of operating aReverse Path Communication System of claim 7 wherein the step ofsimultaneously transmitting further comprises: dynamically modifying, inresponse to identified modifications to the stream of content framescorresponding to the aggregated end user input data, the stream ofcontent frames yet to be transmitted to the set of selected ones ofwireless end user devices and transmitting the modified the stream ofcontent frames to the set of selected ones of wireless end user devices.9. The method of operating a Reverse Path Communication System of claim7 wherein the step of simultaneously transmitting further comprises:associating the end user input data received from the end users withcorresponding stream of content frames.
 10. The method of operating aReverse Path Communication System of claim 8 wherein: the step ofassociating further comprises: defining a time period for use by thefeedback synchronizer during which time period the end user input datareceived from the end users is associated with at least one of thepresent frames of the stream of content frames stored in the buffer. 11.The method of operating a Reverse Path Communication System of claim 10wherein the step of associating further comprises: processing theaccumulated end user input data received from the end users to acomposite content revision for stream of content frames.
 12. The methodof operating a Reverse Path Communication System of claim 7 furthercomprising: transmitting end user input data, associated withcorresponding stream of content frames, to a central content source thatis generating the corresponding stream of content frames via a path thatextends from the communication network to the central content source.